Nozzle



y 29, 1952 R. P. NORTHUP 296053441 NOZZLE Filed Aug. 25, 1950 Inventor: Robert F Northup,

HIS Attorney.

Patented July 29, 1952 NOZZLE Robert P. Northup, Round Lake, N. Y., assignor to General Electric Company, a corporation of New York Application August 25, 1950, Serial No. 181,457

' 4 Claims. (01. 299-443) ularly, it relates to a nozzle of improved design for the discharge of liquid in a uniform, substantiallysolid conical spray. l

In Combustion apparatus wherein one liquid is burned in the presence of another fluid, it is essential that the two fluids be intermixed to the highest possible degree so that complete and efficient combustion will take place. To this end, it is necessarythat the fluids be introduced'into the combustion chamber in an atomized. condition. It is also desirable that the distribution of atomized particles be uniform at any crosssection of the spray perpendicular to the spray axis so that the reactant or fuel and oxidizing fluids may burn efiiciently and without pulsation due to poorrnixing.

Nozzles of various designs have been proposed to distribute the atomized particles in a uniform pattern into the combustion chamber. However,

such nozzles have heretofore tended to be complicated in structure and have involved excessive energy losses due to substantial pressure drops through the nozzles. Prior nozzles are also deficient in that, despite their complicated structure,.they do not produce a'spray which is uniformly atomized. They are also severely limited in their applications, since they operate eificie'ntlyonly at a specific pressure drop or over a narrow range of pressure drops outside of which the atomizing ability falls sharply and the spray ly at low pressure drops.

' A still further object of this invention is to provide a nozzle which produces a stable atomized solid cone spray over a wide range of liquid feed pressures.

Other objects will become apparent from a consideration of the following description and the drawing in which Fig, 1 shows a cross-sectional plan view of a typical embodiment of the present nozzle and Fig. 2 is an end elevational view of the nozzle taken from a downstream direction.

It has been found that a nozzle which will deliver a substantially uniform, finely atomized conical spray of liquid may be readily provided.

It has further been found that such a nozzle may be provided by onehaving a flaring and, preferably, a conical recess for the discharge of liquid, having its apex upstream and three or more holes leading into the recess at such angles that jetsof liquid issuing from the holes intersect or impinge at'a common point on the axis of and wholly within the recess. Preferably, the angle between the axis of the recess and the holes is the same in each case. Preferably, also, the holes enter the recess at points which are equidistant from the apex of the recess and are uniformly arranged around the recess' By having the discharge holes uniformly arranged about the recess and describing like angles with the recess the highest degree of atomization and spray shape and uniformity is achieved.

It is also important that the jets of liquid issuing from the discharge holes intersect, collide or impinge wholly within the recess. In this manner the colliding particles from the jets are thoroughly atomized and confined by the walls of the conical recess so that the resultant spray issues as a solid cone of substantially uniformly distributed particles. If the jets are allowed to collide outside the confines of the conical recess, apoorly atomized, irregularly shaped, and non-uniform spray results. Additionally, when theljets are allowed to impinge outside the recess at wide angles, there is a tendency for a backwash-of fuel to collect around the nozzles, such backwash tending to burn out or destroy the injectorand the surrounding area. This fault, common in many injector designs, is avoided in the'present invention which effectively directs all flow away from the nozzle. It has been found in actual practice that at least three dischargeholes should be used in order to achieve a solid cone spray in which the density of atomized particles is substantially the same in any plane through the spray and perpendicular to the axis thereof. Two holes have been found to produce an irregularly shaped non-uniform spray. Four holes, as in the drawing, arranged ninety degrees from one another around the nozzle recess have been found to give a symmetrical, uniform, and desirable spray. It will be understood, of course, that the number of holes may also be greater than four without detracting from the desirable characteristics of the present nozzle.

The degree 0f atomization of the spray produced by the present nozzle may be changed by varying the entry angle of the discharge jets 3 with relation to each other or the axis of the nozzle recess. For example, when the upstream angle between two opposing jets is relatively large or approaches 180 degrees, the liquid is atomized to a greater degree, due to the force of the collision and mixing, than when the same angle is relatively smaller. The angle described by the faces of the recess may also be changed to alter the shape of the spray, or, in conjunction with the entry angle of the jets, to vary the degree of atomization.

Reference is now made to the drawing for a specific embodiment of the present nozzle, which embodiment it will be appreciated, may be varied without departing from the spirit of the present.

invention. The nozzle I typically is constructed of a solid head 2 having wall 3 defining a conical recess 4 with its apex located upstream as shown. The discharge of liquid through the nozzle is provided for by holes 5; As pointed out above, the number of such holes is greater than two and preferably fourthough any number above'two may be, used. As also pointed out heretofore, theholes 5 preferably are located equidistant from the, apex of conical recess 4 and in uniform fashion around the recess so that jets of liquid issuing therefrom intersect at a common point on the axis of, the recess and, within the confines of the. recess. Access of liquid to-holes '5 is providedfor. by the cutaway upstream part of the nozzle which provides an annular passage 6 in conjunction with a conduit such as l to which the nozzle may be attached by threads, or brazing or welding, as shown at 8.

In operation, the liquid to be discharged from the nozzle is fed through conduit or tube 1, through passage 6 and into holes 5. The liquid is fed from holes 5 in jets which intersect, impinge or meet at a common point on the axis of recess 4 and within the confines ofthe recess. The jets collide forcibly with one another and the particles thereof With the wall of the recess to produce a solid atomized spray which is conical in shape and which has a uniform density at any cross-section perpendicular to the spray axis.

, The: present nozzle is particularly characterized by the delivery of a solid conical spray having. a uniform density at any cross-section perpendicular to the spray axis. Such spray produced by the nozzle is further unchanging in i shape over a wide range of pressure. For example, a nozzle of the present design having a cone diameter of one-half inch and four dischargeholes about 0.05 inch in diameter arranged as shown in the drawing is characterized by 4 intended to protect all variations which do not depart from the spirit and scope of the present invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A nozzle for discharging liquid, saidnozzle having an outwardly flaring recess for the discharge of liquid and means forintroducing liquid into said recess, said means comprising at least three holes leading through the wall of and into said recess, uniformly spaced around said recess and equidistant from the upstream end of said recess, the axes of said holes being so disposed as to causejets of liquid issuing therefrom to impinge wholly within said recess at a common point on the axis of said recess.

2. A nozzle for discharging liquid in a solid conical spray having a uniform density at any cross-section thereof perpendicular to the spray axis, said nozzle having an outwardly flaring recess therein and at. least three liquid discharge holes. leading through the wall of and into said recess, theaxes of said holes being equally spaced around said wall of said recess and so disposed that liquid jets issuing therefrom intersect wholly within said recess at a common point on the axisof said recess.

3-. vIna nozzle for discharging liquid in a solid conical spray having a uniform density crosssection, a solid head portion having; a conical recess therein with the apex upstream and means for: introducing liquid into said recess, said means comprising at least three holes leading through the'wall of and into said recess, the axes of'said holes being equally. spaced around said wall of said recess and so disposed that liquid jets issuing therefrom intersect wholly within said recess at a common point; on the axis of said recess.

4'. A nozzlev for discharging liquid in. a solid conical spray having a uniform density at any cross-sectionthereof perpendicular to the; spray axis, said nozzle having a cone-shaped recess therein with the apex upstreamand at least three liquid discharge holes of equal size leading, through the'wall of and into said recess, the axes ,of said holes being: uniformly spaced around said wall of said recess, equidistant from the apexof said recess, at the same. angle to the axis of said recess and so disposed that liquid jets issuing: therefrom intersect. wholly within said recess at a'common point on the axis of. said recess.

ROBERT P. 'NORTHUP.

REFERENCES CITED.

The following references are of record in the file. of this patent;

UNITED STATES PATENTS Number Name Date 2,311,266 Svet Feb. 16, 1943 2,343,305 Larter Mar. '7, 1944 2,499,092 Burnam Feb- 28, 1950 

